[Fe II] 1.64 um Features of Jets and Outflows from Young Stellar Objects in the Carina Nebula

TL;DR

This study uses [Fe II] 1.64 μm imaging to identify and analyze jets and outflows from young stellar objects in the Carina Nebula, revealing new features and estimating mass loss rates, contributing to understanding star formation processes.

Contribution

First detection of [Fe II] jets and outflows in the Carina Nebula with new Herbig-Haro object identification and analysis of outflow properties relative to YSO parameters.

Findings

Eleven jet/outflow features detected, including a new HH candidate.

Outflow mass loss rates are consistent with previous models for some IFOs.

Jet-driving YSOs are likely low- or intermediate-mass stars.

Abstract

We present [Fe II] 1.64 {\mu}m imaging observations for jets and outflows from young stellar objects (YSOs) over the northern part (~ 24'x45') of the Carina Nebula, a massive star forming region. The observations were performed with IRIS2 of Anglo-Australian Telescope and the seeing was ~1.5"+-0.5". Eleven jet and outflow features are detected at eight different regions, and are named as Ionized Fe Objects (IFOs). One Herbig-Haro object candidate missed in Hubble Space Telescope H{\alpha} observations is newly identified as HHc-16, referring our [Fe II] images. IFOs have knotty or longish shapes, and the detection rate of IFOs against previously identified YSOs is 1.4 %, which should be treated as a lower limit. Four IFOs show an anti-correlated peak intensities in [Fe II] and H{\alpha}, where the ratio I([Fe II])/I(H{\alpha}) is higher for longish IFOs than for knotty IFOs. We estimate the outflow mass loss rate from the [Fe II] flux, using two different methods. The jet-driving objects are identified for three IFOs (IFO-2, -4, and -7), for which we study the relations between the outflow mass loss rate and the YSO physical parameters from the radiative transfer model fitting. The ratios of the outflow mass loss rate over the disk accretion rate are consistent for IFO-4 and -7 with the previously reported values (10^-2-10^+1), while it is higher for IFO-2. This excess may be from the underestimation of the disk accretion rate. The jet-driving objects are likely to be low- or intermediate-mass stars. Other YSO physical parameters, such as luminosity and age, show reasonable relations or trends.